Mitosis and Meiosis Vocabulary
These terms relate to the Production of body cells: Mitosis
Surface area to volume ratio - the amount of surface covering an object
(or a cell) compared to the volume contained within; as surface to volume
ratio decreases in cells, division becomes necessary
Cell Division - the process of creating two new cells
Mitosis - when the nucleus itself divides into two new nuclei
Cytokinesis - when the rest of the cell divides to form two new daughter
cells
Chromatin - when the DNA inside the nucleus appears as disorganized,
long strands
Chromosomes - when the DNA coils tightly, shortens and thickens prior to
mitosis
DNA molecule - another name for a chromosome; contains the genes
Replication - the process of chromosomes making exact duplicates
Sister chromatids - the two sides of the "X" formed by replicated
chromosomes
Centromere - a central protein bundle that connects sister chromatids
Autosomes - all chromosomes except for the sex chromosomes
Genes - codes within DNA that specify a particular trait
Alleles - two alternate forms of each gene (such as blue eyes or brown
eyes)
Somatic cells - All of the body cells
Gametes - sperm and egg cells, also referred to as sex cells
Diploid number - the total number of chromosomes in normal body cells;
two matching homologs of each kind
Cell cycle - the entire life cycle of the parent cell
Interphase- the cell is carrying out its normal everyday cell activities as
well as preparing for the Mitotic phase
G1 and G2 phases - gap phases; G1 is mostly growth and development G2
occurs after replication of chromosomes and involves replication of additional
organelles and membranes in preparation for cell division
S phase - synthesis of new DNA; also called replication
Prophase -the first phase of mitosis characterized by a disappearance of
the nuclear membrane and nucleolus
Spindle basket - This structure will assist in pulling apart the doubled
chromosomes
Metaphase - the second phase of mitosis where all of the doubled
chromosomes move to the center of the cell, called the equator
Anaphase - the third phase of mitosis where the spindle fiber shorten from
the poles, pulling the doubled chromosomes apart from each other, toward
the poles of the cell
Telophase - the final phase of mitosis characterized by the separated
chromosomes reaching the poles of the cell. The nuclear membrane and
nucleolus begins to reappear around each set of chromosomes
Cell plate - a structure which eventually forms a cell wall that begins to
grow out from the center and merely separates the two daughter cells
Microtubule - organizing center which performs the job of the centriole in
plants
These terms refer specifically to meiosis
Genetic recombinations - different ways chromosomes can provide
variation in the species depending on which chromosomes are inherited and
whether or not crossing over occurs
Sex chromosomes - in humans, XY designates a male; XX designates a
female
Crossing over - each chromatid may exchange a part of itself with its
homolog as it crosses over the other during late prophase I or early
metaphase I of meiosis
Homologous pairs - matching chromosomes that each came from either
the father or the mother; homologs code for different versions of the same
genes
Meiosis - the division of a nucleus that results in four nuclei with one half
the original number of chromosomes; used to produce gametes
Haploid number - one half the total number of chromosomes in a normal
body cell; one of each kind of homolog
Oogenesis - meiosis that produces eggs (ova)
Ovum - an egg resulting from oogenesis
Spermatogenesis - meiosis that produces sperm
These terms relate to testing of the fetus for any genetic
disorder:
Nondisjunction Mutations - improper separation of sister chromatids may
result in a cell having one too many chromosomes (trisomy) or not having
one of a certain chromosome (monosomy)
Karyotype - a photograph of an individual's chromosomes
Amniocentesis - when a long needle withdraws fluid around fetus; some of
the embryo's cells that have sloughed off into the fluid will be collected and
examined
Chorionic Villi Testing - scraping a few cells from villi of the placenta
which connect fetus to mother in the uterus
Ultrasound - images formed by sound waves can be converted into pictures
of the uterus to determine gross structural abnormalities of the fetus; this is
a safe and non-invasive procedure